The Demon of Lust
by Xykonmenace
Summary: Jace has an encounter with Asmodeus, demon of lust.Enslaved by the demon,Jace must collect the seed of other male Shadowhunters for the demon. Chpater One is Jace and the demon/OC, chapter two will be a Jalec and Chapter Three will be a threesome. RatedM.
1. Chapter 1

Disclaimer: The Mortal Instruments series and all things, concepts and characters related to it are not mine.

This is set after CoB

Jace has an encounter with a Greater Demon even he could not overpower.

The Demon's Flesh

Jace entered the abandoned building, his Sensor in one hand and a seraph blade in the other. The thrumming of the Sensor told him that there was a demon nearby, and probably a challenging opponent.

He gripped the seraph blade's hilt tightly, reminding himself that this was good, a challenging fight to break the awful mood that had been plaguing him since the battle at Renwick's. He wanted to flee from Clary, to flee from both lies and truth.

He entered a huge room, the ceiling twenty feet above him. Shadows lay dark upon every corner and columns of darkness littered the empty space. There were no windows but someone had installed weak fluorescent lights on the walls.

The sensor was going crazy; the thing was buzzing and beeping like a hive. Jace shoved it in his pocket and ran a hand through his golden hair. "Hey, Demon!" he called in the expanse of the room, "Show me what you got!"

With a sound like an eel sliding in water, the two tentacles shot down from above Jace, coiling rapidly around his arms and jerking the Seraph blade from his grip. The shimmering weapon clattered away from the struggling Sahdowhunter and lay twenty feet away. Four more tentacles shot down from the shadow shrouded ceiling and coiled around his ankles and his waist.

A man-shaped figure dropped down from the ceiling like a bat detaching from a cavern wall. It landed a few feet away from Jace and he saw that at least a dozen tentacles grew out of its back. The figure walked out of the shadows and into a lit space in front of Jace.

"So you're the demon?" Jace asked, still trying to struggle from his fleshy bonds. The demon was tall, taller than him by half a foot. The face was uncannily handsome, with a seductive quality to its features, from the red lips to the naughty eyes. Its muscles were perfectly defined and toned, the tanned golden skin gleaming as if from massage oils. Judging from the impressive organ hanging between its legs, it was male.

The demon walked closer, the tentacles restraining Jace tightened a little, "Not just a Demon, Nephilim," the demon remarked, "A Greater Demon. I am Asmodeus, Demon of Lust." Jace laughed, "They couldn't keep the pants on you alright."

The demon smiled and pulled Jace closer. Jace was now hovering mere inches from the demon. The musky and alluring scent of male arousal wafted from the demon and Jace felt a warmth spread down his body and roil in his groin.

Asmodeus put a hand on Jaces cheek and leaned forward. Jace felt the tips of their noses touch and he blushed, despite himself. "You area very _fine_ specimen, aren't you?" the demon whispered. He locked eyes with Jace, gold meeting poisonous green. Asmodeus laughed and licked his lips, "You shall be very useful to me, after I have had my fun with you."

"How about lets have fun now?" whispered Jace, and before the demon could react he headbutted him with all his strength. The demon yelled in pain and stumbled backward, but the tentacles holding Jace did not loosen. The demon stood up and looked at him, but Jace saw nothing but an even greater look of lust n the demon's face.

"I like it rough," the demon said, smiling. A tentacle shot forward and paused in front of Jace's face. Asmodeus walked closer, but not too close. "You shall suck this, Shadowhunter, and you will love it. You will suck this like a cock, which you will crave soon" Jace was about to reply when the tentacle stuffed itself into his mouth. Jace gagged, and was resolved to bite the damned thing when he tasted something leaking from the tentacle/

It was salty and sweet and each drop gave Jace pleasure that shot through his body. He began to swirl his tongue around the tip of the tentacle, and he moaned inwardly. Asmodeus laughed and Jace felt the other tentacles rip-off his shirt. Jace would have fought, but his mind was occupied with the joy of sucking the tentacle off. The tentacle pushed in and out of his mouth, and whenever Jace felt the tentacle began to withdraw, he moaned.

Suddenly the tentacle withdrew itself entirely and Jace whimpered at the loss of the sensation. Asmodeus sauntered in front of him, rubbing his own genitals. Already the demon was half-hard.

"Do you want more of my seed?" the demon asked.

Jace whimpered in response, and inside his head a voice scolded him. _We never whimper! _Bur lust overrode his training. "Please," begged Jace, "I want more!"

Asmodeus laughed. He walked right up to Jace and rubbed the Nephilim's bulge. "Do you want it bad?" the demon asked.

"Bad, real bad!"

"Do you like sucking my tentacles, my other cocks?"

"Yes! Yes! I love sucking them!"

Asmodeus nodded, "Then they are yours." The tentacles ripped apart Jace's clothes and dropped him on the cold floor. Jace stood up, and instead of reaching for his seraph blade, began to furiously suck on two tentacles at once, taking the tips of both into his mouth at the same time. With his hands he masturbated two more tentacles, their sweet seed leaking from their tips. Jace was now lost lust.

The demon tugged at his own erection, his clawed hands rubbing the tip. This was one eager slut of a Shadowhunter. Probably had a lot of repressed emotions. He smiled and let him play with his tentacles.

A tentacle snaked around Jace's own shaft and stroked it. "By the Angel! Moaned Jace, his back arching with pleasure. Sweat poured down his face and his devil's lips were parted in ecstasy before clamping around a tentacle, sucking on the phallic appendage to stop himself from screaming. His golden hair was plastered on his forehead with sweat, but he didn't care.

"Take me, Asmodeus," Jace begged, "Fuck me in the ass! Please!" Jace was on all fours, tentacles clutched on both fist and two being tickled by his tongue. One was still pumping his erection whilst another massaged his balls, the tip squeezing and rolling the orbs, He was covered with the sticky seed of the tentacles.

"What is your name, Shadowhunter?" the demon asked. One of his own tentacles was masturbating him, his hands massaging his nipples instead. He moaned a little as he pinched one.

"Jace, Jace Morg- Wayland, Jace Wayland."

"Very well, Jace. I shall fuck you. But after, I must get something in exchange."

Jace nodded, "Whatever, just bury your meatshaft in me."

Asmodeus shook his head. Never had he encountered such an eager cock-slave. Asmodeus walked behind Jace nad kneeled to inspect Jace's virgin hole. He lowered a tentacle and pushed into it experimentally.

"Oh God," moaned Jace, drooling. His hands were clenched with pleasure,. Asmodeus pushed the tentacle in deeper and it grazed Jace's prostate. The Shadowhunter nearly shouted in pain and pleasure but instead shoved a tentacle into his mouth and began sucking on it.

The demon knelt as well and pushed his own member into Jace, but did not remove the tentacle. "Ah! Ah!" Jace exclaimed, the feeling of two organs inside him caused more pleasure than pain and when the demon began thrusting both, Jace literally screamed with delight.

Asmodeus plunged in and out of Jace, tentacle and penis alike spearing the boy. The demon pulled Jace against him and stood up, still thrusting into Jace. Tentacles teased Jace's nipples and his mouth. He was still pumping two, rubbing their oiled tips on his face. He spat out the tentacle he had been sucking to shout in pleasure.

"Ah! Fuck! Fuck! Ah! Yeah!" The Shadowhunter yelled. Asmodeus smiled and nibbled at Jace's neck, and he reached around and stroked the hardorgan bobbing between Jace's thighs. Asmodeus begun to thrust faster and faster, and Jace could feel both of them were about to cum.

Jace moaned and felt himself stiffen and buck as he ejaculated, thick strands pf semen shooting out of his cock. Asmodeus moaned too and all his tentacles and his copck shot out pearly sperm as well, bathing the two in a shower of male fluids. Globs of it were stuck in ther hair, dribbling down their chiseled chests and splattered on their handsome faces.

Jace slumped against the demon and the demon lowered both of them to the floor. Jace pressed against the demon and licked cum off his lips and hands. It was delicious. The demon licked his ear and whispered, "You promised me anything after we fucked." Jace smiled his devil's smile and turned to face the handsome demon, their s\chests sticking together because of the sperm. "Anything."

The demon kissed him and Jace tasted sperm and saliva swirl in his mouth. He felt something small and round slip into his mouth before he swallowed it. Jace pulled away, "What was that?"

"A demon seed." Asmodeus stood, "From now on, you, Jace , are my cock-whore. You will call me master in my presence. And now for your first mission: bring me the seed of two more Shadowhunters, male Shadowhunters. I need it for a ritual."

Jace stood and in his nakedness, he was still like a god or a fallen angel, he knelt in fron of the demon. "My mouth, my cock and my ass are your, Master." The demon smiled and grazed the tip of his member on Jace's lips. "Concentrate, cock-slave. Do you have a target in mind?"

Jace took his new master's cock into his mouth and pulled itout again before speaking. "I have just a candidate at home. He's gonna love the new me." Jace stroked his master's cock as he began to plot how best to seduce Alec.

End of Chapter One.

Chapter Two will invole Alec'sown conversion into Asmodeus' slave and Chapter Three will feature a threesome between Luke, Alec and Jace!


	2. Chapter 2

The Shadowhunters' Descent

Alec woke in his bedroom at the institute, his grey shirt and boxers not protecting him from the slight morning chill. He sat up in bed and watched the motes of dust swirl in the weak rays of dawn that played in his room.

Alec first wondered why his crotch felt weird, and then he realized he was rock hard, the grey boxers squishing his genitals uncomfortably. He blushed even though he was alone. He rubbed the bulge between his legs, moaning softly as pleasure rippled upward, throwing his head back. Then he remembered why he was aroused.

Jace had gotten home past midnight, his face tired but happy, for some reason. Alec had gotten out of his room and asked, "Where have you been? Izzy and I have were worried you got ambushed by demons or something." Jace had found that funny, and had chuckled, "The demon took care of me alright." Alec raised an eyebrow, "Took care of you?" Jace had laughed and hugged him tight. Alec could not suppress his erection, being that close to Jace always made him horny. The golden-haired youth smelt of leather, blood and smoke…but he alse detected the musky scent of male arousal lingering heavily around Jace.

More distressing (or was it more arousing?) was that Jace was hard, too. Their erections pressed against each other through their clothing and Alec nearly sighed with contentment. Jace had broken the hug off and cloistered himself in his room.

Alec opened his eyes and shove the memory away. He shook his head and thoguth instead of the types of demons, washing his face and leaving his room no longer hard.

As he walked past Izzy's room he saw note tacked on the door,t read:

"Weekend underground with Meliorn. ;) Don't tell mom. Love you lots, Isabelle"

Shaking his head with amusement and concern he walked into the kitchen. Sunlight, at first slightly pinkish, but now a little orange, filtered in through the windows of the tiled space. Alec opened the fridge and started poking around inside. Nothing edible but a carton of milk, he thought glumly. He brought it out and began to drink it.

The sound of bare feet padding down the hall alerted him of Jace's approach. He turned his back to the noise and instead busied himselfonce more with the contents of the fridge.

"Morning," came Jace's voice. It was clear of drowsiness and seemed almost excited.

"Nothing to eat," Alec replied, his head still inside the fridge.

"Can you hand me the milk?" asked Jace from behind Alec.

Alec took one last swig, turned to hand it to Jace and almost choked on the milk.

Jace was wearing nothing but tight black shorts, the material clinging tightly to his crotch and upper thighs. They hinted everything from the musculature of his legs to the obvious erection he was sporting. The younger Shadowhunter was leaning against the counter, his hips thrust forward. Golden sunlight now spilled over his ridiculously hot form, his hair shining with the light.

"I-It's a bit cold this m-morning, isn't it?" Alec mumbled, lowering his gaze. Jace smiled coyly and walked forward. He took the carton of milk from Alec. "Yeah it kinda is. Could use something hot to eat."

Alec flushed crimson, but he couldn't keep the image of Jace nearly naked out ofhis head. He hardened, his cock tenting the front of his boxers. Jace stepped closertohm,his bare chest barely four inches from Alec's.

"Found something that's much nicer to eat," Jace whispered, and he knelt in front of Alec's raging hard-on. "What are you doing Jace?" Alec breathed, his face flushed with wanting. Jace said nothing but bit the garter of Alec's shorts. Alec could feel his cock pressing against the kneeling boy's throat.

Jace pulled down Alec's shorts with his teeth, the garter and the fabric rubbing the whole length of Alec's erection. Jace was stroking his own hard penis through his thin garment, precum staining the material.

Alec suppressed a moan, but he bucked his hips as Jace licked the head of his throbbing manhood. "Jace, Jace…S-Stop." Jace merely looked up, his chin coated with saliva and said, "You don't really mean that, do you Alec?" before deepthroating his parabatai. Alec moaned out loud this time, and gripped the sides of Jace's hair as he felt the tongue curl around his shaft.

"No, no, I didn't meant that. K-Keep sucking me." Alec sighed through gritted teeth. Jace detached his devil's mouth from Alec with a popping sound and tackled Alec's balls instead. He licked them, the two fleshy orbs covered slightly with pubic hair.

"By the Angel, where did you learn to do these?" Alec gasped. Jace wrapped an arm around Alec's waist and continued to suck him off. "I'll tell you afterwards" Jace promised. The golden haired boy removed his only garment and was jacking off, his deft hands massaging the tip of his own member while his mouth played games with Alec's.

"Jace, I'm going to-I'm going to- Aaah!" Alec half screamed and half moaned as he came. Jace took some of his friend's semen in his mouth, but let some splatter onhis gorgeous face.

As Alec panted, knees shaking from the sheer pleasure and fulfillment, Jace stood, his unsatisfied erection pointing upwards, and kissed his parabatai. Alec opened his mouth to receive Jace's tongue, but instead he got a gush of his own cum, the warm liquid mixed with Jace's spit sloshing in his mouth,

Alec grew hard again with the tase of himself, but as he kissed Jace, their tongues snaking and bathing in the mixture of sperm and saliva, he felt Jace push something small and round into his mouth.

Alec tried to feel what it was, but Jace's tongue pushed it into his mouth and, lubricated by his cum, it slid into his throat. Alec gagged, dropped to his knees and was about to shout when the cloud of demonic lust and wanting, the want to serve and the want to be enslaved by a strong presence overcame him.

Jace leaned back as he watched the demon seed take control of Alec. As Jace had found out last night, as he and Asmodeus fucked in every position imaginable, the seed gave incredible stamina and sperm production to any who swallowed it. Asmodeus had given him four. Jace stroked himself as he remembered getting penetrated and sucking his Master's tentacles.

A wet and hot mouth engulfed the tip of his penis, and he smiled down at Alec. Alec was now a cock-slave as well, a whore to be used by Asmodeus to provide him with Shadowhunter sperm. Jace ran a thumb down Alec's face, so eager to please virtually anyone and shinign with contentment as he sucked Jace's cock.

"You are sealed to him now," Jace whispered. Alec nodded vigorously, still greedily sucking Jace,

"Well, I need one more cock-whore for the Master," Jace whimpered at the memory of his Master's erect manhood. Then he had an idea. "Alec, we're going out tonight. To the Hunter's Moon." Alec nodded again, his face buried in Jace's balls. Jace moaned a little before dragging Alec to his feet, "We'regoing to pay Luke a visit." Alec groaned as Jace teased his hole with the tip of his dick.

"But we have the whole day to have fun, Alec."Jace said.

Alec nearly came from the seduction in Jace's voice.


End file.
